A painting 3D texture printing method applying a 3D scanner and a UV inkjet printer

Abstract

The application provides a painting 3D texture printing method using a 3D scanner and a UV inkjet printer, and the method comprises the following steps: a data acquisition step: color image data and three-dimensional point cloud data containing height information of a painting original work are acquired; a data mapping step: according to the statistical distribution characteristics of the height information, the height value is divided into at least four intervals, the height value in each interval is respectively mapped to a gray scale value by using a preset nonlinear mapping curve, and at least four original gray scale maps corresponding to the intervals are generated; a layered processing step: edge feathering and layered superposition processing are performed on the original gray scale maps, and at least four layered printing gray scale maps are generated; and a layered printing step: according to the layered printing gray scale maps, a transparent UV varnish layer corresponding to each layered printing gray scale map is sequentially printed on a printing material by using the UV inkjet printer. The application realizes high-fidelity, high-precision and high-efficiency copying of the painting 3D texture, and has outstanding substantial characteristics and significant progress.

Description

Technical Field

[0001] This application relates to the field of artificial intelligence technology, specifically to a method for printing 3D textures of oil paintings using a 3D scanner and a UV inkjet printer, an energy consumption prediction device, electronic equipment, and a storage medium. Background Technology

[0002] Oil paintings, with their rich color layers and unique brushstroke textures, exhibit a strong artistic expressiveness, and their three-dimensional surface texture is an important component of the original artwork's artistic value. Traditional oil painting reproductions mostly use flat printing techniques, which can only reproduce colors but lose textural information.

[0003] In recent years, with the development of 3D scanning and digital printing technologies, methods for stereoscopic reproduction of oil paintings combining 3D scanning and UV inkjet printing have emerged. For example, patent application number 202110367877.4 discloses a method for stereoscopic reproduction of oil paintings based on stereoscopic scanning and a UV inkjet printer. This method creates a grayscale color chart image of 0%-100% and establishes a linear correspondence between height and grayscale, converting the height information of the oil painting surface into a grayscale spot color channel, which is then printed out in one go by a UV inkjet printer. This method represents a significant improvement over traditional planar reproduction, but it still suffers from the following shortcomings: First, its global linear grayscale mapping strategy makes it difficult to simultaneously and accurately reproduce the subtle textures (low-height areas) and thick layering (high-height areas) commonly found in oil painting brushstrokes, easily leading to loss of detail or significant distortion. Second, the single-printing method, when faced with steep brushstroke edges, is prone to ink droplet accumulation, creating a "staircase effect" that makes the texture edges of the reproduction stiff and the transitions unnatural. Third, the entire printing process is open-loop controlled, lacking real-time detection and correction of the actual printing height, making it difficult to guarantee consistency during batch reproduction. Therefore, how to improve the accuracy of 3D oil painting texture printing while eliminating the staircase effect and enhancing the realism of complex brushstroke reproduction is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] The problem solved by this invention is how to improve the accuracy of 3D texture printing of oil paintings while eliminating the staircase effect and enhancing the realism of complex brushstrokes.

[0005] To address the aforementioned problems, this invention provides a method, printing system, electronic device, and storage medium for printing 3D textures of oil paintings using a 3D scanner and a UV inkjet printer.

[0006] In a first aspect, the present invention provides a method for printing 3D textures of oil paintings using a 3D scanner and a UV inkjet printer, comprising the following steps: Data acquisition steps: Acquire color image data and 3D point cloud data containing height information from the original oil painting; Data mapping steps: Based on the statistical distribution characteristics of the height information, the height value is divided into at least four intervals, and the height value in each interval is mapped to grayscale value using a preset nonlinear mapping curve, generating at least four original grayscale images that correspond one-to-one with each interval. Layered processing steps: The original grayscale image is feathered at the edges and layered overlay is performed to generate at least four layered printed grayscale images; Layered printing steps: Based on the layered grayscale images, use a UV inkjet printer to sequentially print transparent UV varnish layers corresponding to each layered grayscale image on the substrate to construct the three-dimensional texture of the oil painting.

[0007] Optionally, in the data mapping step, the preset nonlinear mapping curve includes a logarithmic curve and an exponential curve; for the interval with a low height value, the logarithmic curve is used to amplify fine textures; for the interval with a high height value, the exponential curve is used to compress excessively thick stacks.

[0008] Optionally, in the data mapping step, the preset nonlinear mapping curve adopts the following piecewise nonlinear mapping formula: ; in, This is the original height value. The mapped grayscale values; , The total height interval is divided into at least four sub-intervals based on the statistical distribution characteristics described above; , (This refers to the low altitude range.) >0 is the amplification factor; [ , () represents the medium altitude range, and a linear mapping is used; , [ represents the high altitude range, 0 <] <1 indicates a compression index; , These represent the minimum and maximum output grayscale values ​​for the corresponding intervals.

[0009] Optionally, the edge feathering in the layering process specifically involves: identifying regions in the original grayscale image where the grayscale gradient exceeds a preset threshold, performing Gaussian blurring on these regions, and generating a transition grayscale image.

[0010] Optionally, before the layered printing step, a path planning step is also included: according to the grayscale gradient direction of the layered printed grayscale image, the scanning direction of the UV inkjet printer is set so that the ink droplet accumulation direction is consistent with the brushstroke direction of the original oil painting; for areas where the grayscale gradient exceeds a preset threshold, a cross-printing mode is enabled.

[0011] Optionally, the layer printing step specifically includes: printing each layer in sequence from low to high height; pre-curing each layer using a UV lamp with a first power after printing; and finally curing all layers using a UV lamp with a second power higher than the first power after printing.

[0012] Optionally, it also includes a closed-loop correction step: during or after the layered printing process, the actual height of the printed texture layer is scanned and compared with the original height in the three-dimensional point cloud data. Based on the comparison result, the parameters of the nonlinear mapping curve or the ink jet volume of the UV inkjet printer for subsequent printing are dynamically corrected.

[0013] Optionally, after the data acquisition step, a registration step is also included: registering the color image data with the three-dimensional point cloud data in spatial coordinates to generate an initial three-dimensional model with color information.

[0014] Optionally, before the layer printing step, a color layer printing step is further included: printing a color image layer on the substrate according to the color image data, and performing a semi-curing treatment; the layer printing step is performed on the color image layer.

[0015] Secondly, embodiments of the present invention provide an oil painting 3D texture printing system, comprising: The 3D scanning unit is used to acquire the three-dimensional point cloud data of the original oil painting; A color imaging unit is used to acquire color image data of the original oil painting; The data processing unit is used to execute the data mapping step and the hierarchical processing step; A UV inkjet printer, loaded with CMYK color ink and at least one transparent UV varnish, is used to perform the color layer printing step and the layer printing step. The closed-loop feedback unit, including an online 3D scanner and a comparator, is used to perform the closed-loop correction step.

[0016] Optionally, the UV inkjet printer includes multiple printhead groups, wherein at least one printhead group is dedicated to spraying the transparent UV varnish, and the nozzle arrangement density of the printhead group dedicated to spraying the transparent UV varnish is higher than the nozzle arrangement density of the printhead group spraying CMYK color ink.

[0017] Thirdly, embodiments of the present invention provide an electronic device, including a processor, a communication interface, a memory, and a bus, wherein the processor, the communication interface, and the memory communicate with each other through the bus, and the processor can call logical instructions in the memory to execute the steps of the method provided in the first aspect.

[0018] Fourthly, embodiments of the present invention provide a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the oil painting 3D texture printing method using a 3D scanner and a UV inkjet printer as described in the first aspect.

[0019] The beneficial effects of the oil painting 3D texture printing method using a 3D scanner and a UV inkjet printer of the present invention are as follows: By performing nonlinear mapping on the surface height data of oil paintings, suitable mapping curves can be applied to different height ranges (such as areas of fine texture and areas of thick paint stacking), significantly improving the resolution and reproduction accuracy of complex brushstroke layers. Through layered printing, edge feathering, and optimized path planning (such as cross printing and direction matching), the step effect produced by traditional single-printing methods is effectively eliminated, resulting in natural transitions at the edges of the printed texture and brushstroke directions consistent with the original artwork. The introduction of online detection and closed-loop correction mechanisms, which compare the actual printed height with the original height in real time and dynamically adjust printing parameters, greatly improves the fidelity and consistency of batch reproduction. In addition, the step-by-step pre-curing and final curing strategies enhance the interlayer bonding force, giving the reproductions better physical durability. In summary, this invention achieves high-fidelity, high-precision, and high-efficiency reproduction of 3D textures in oil paintings, possessing outstanding substantive features and significant progress. Attached Figure Description

[0020] Figure 1 This is a flowchart of a method for printing 3D textures of oil paintings using a 3D scanner and a UV inkjet printer, as described in an embodiment of the present invention. Figure 2 This is a structural block diagram of the oil painting 3D texture printing system in an embodiment of the present invention; Figure 3 This is a structural block diagram of the electronic device in an embodiment of the present invention. Detailed Implementation

[0021] To better understand the purpose, technical solution, and advantages of this application, the application is described and explained below in conjunction with the accompanying drawings and embodiments.

[0022] Unless otherwise defined, the technical or scientific terms used in this application shall have the general meaning understood by one of ordinary skill in the art to which this application pertains. Words such as “a,” “an,” “an,” “the,” “the,” and “these” used in this application do not indicate quantitative limitation and may be singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or modules (units) is not limited to the listed steps or modules (units) but may include steps or modules (units) not listed, or may include other steps or modules (units) inherent to these processes, methods, products, or devices. Words such as “connected,” “linked,” and “coupled” used in this application are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. Normally, the character " / " indicates that the objects before and after it are in an "or" relationship. The terms "first," "second," "third," etc., used in this application are merely to distinguish similar objects and do not represent a specific order of objects.

[0023] like Figure 1 As shown in the embodiment of the present invention, a method for 3D texturing of oil paintings using a 3D scanner and a UV inkjet printer includes the following steps: S1: Data acquisition steps: Acquire color image data and 3D point cloud data containing height information of the original oil painting; S2: Data mapping step: Based on the statistical distribution characteristics of height information, the height value is divided into at least four intervals. The height value in each interval is mapped to grayscale value using a preset non-linear mapping curve, generating at least four original grayscale images that correspond one-to-one with each interval. S3: Layering process: Perform edge feathering and layer overlay processing on the original grayscale image to generate at least four layered printable grayscale images; S4: Layered printing steps: Based on the layered grayscale images, use a UV inkjet printer to sequentially print transparent UV varnish layers corresponding to each layer of grayscale image on the substrate to construct the three-dimensional texture of the oil painting.

[0024] The height distribution of brushstrokes on an oil painting surface is typically uneven: low-height areas (such as thin coats and smudges) are rich in detail but have small amplitudes, while high-height areas (such as thick coats and scraping) have large amplitudes but relatively gradual changes. If a single linear mapping is used, the small height differences in low-height areas will be compressed to similar gray levels, resulting in loss of detail; excessive height differences in high-height areas may lead to grayscale overflow or stacking distortion. This solution first statistically partitions the height data, and each interval independently uses the most suitable non-linear curve (e.g., a logarithmic curve to amplify differences in low-height areas and an exponential curve to compress differences in high-height areas) to accurately map the height to grayscale values ​​of 0-255. Subsequently, edge feathering is used to avoid abrupt changes at brushstroke edges, and grayscale images of different height intervals are organized into multiple physical layers through layer stacking. Finally, a UV printer sprays transparent varnish layer by layer according to each grayscale image, with each layer corresponding to a height interval, forming a complete three-dimensional shape after stacking.

[0025] For example, a 3D scanner acquires a point cloud (X, Y, Z) of the oil painting surface, and a camera acquires a color image.

[0026] Perform statistical analysis on the Z value and automatically or manually divide it into more than 4 height ranges (such as 0-0.2mm, 0.2-0.5mm, 0.5-1.0mm, 1.0-2.0mm).

[0027] Set a non-linear curve for each interval: for example, use a logarithmic curve for interval 1, a linear curve for interval 2, and an exponential curve for interval 3, etc.

[0028] The height Z of each point is converted into a grayscale value according to the curve of its respective interval, generating 4 original grayscale images (each image represents the relative height within a height interval).

[0029] Gaussian blur (feathering) is applied to the edges (high gradient regions) of each original grayscale image, and then the four images are superimposed from low to high layers to obtain four layered printed grayscale images.

[0030] Controlling the UV printer: First, print the grayscale image corresponding to the lowest layer (spray with transparent varnish), then pre-cur it with UV; then print the second layer, and so on, until finally curing.

[0031] The above scheme solves the contradiction that a single mapping cannot take into account both high and low details. Both fine textures and thick brushstrokes can be reproduced with high fidelity. Layering and edge feathering make the transition between layers smooth, and the printed texture edges are natural without harsh steps. Through precise layer control, excessive or insufficient accumulation is avoided, and UV varnish is saved.

[0032] In the data mapping step, the preset nonlinear mapping curves include logarithmic curves and exponential curves; for the range with low height values, logarithmic curves are used to amplify fine textures; for the range with high height values, exponential curves are used to compress excessively thick stacks.

[0033] It should be noted that, as a specific implementation of the aforementioned nonlinear mapping strategy, this invention also provides a piecewise nonlinear mapping formula for accurately mapping the height values ​​of different height intervals on the oil painting surface to grayscale values. Taking the case of dividing the surface into at least four intervals as an example, it can be expressed as follows: In the data mapping step, the preset nonlinear mapping curve adopts the following piecewise nonlinear mapping formula: ; in, This is the original height value. The mapped grayscale values ​​(range 0-255); , The total height interval is divided into at least four sub-intervals based on statistical distribution characteristics (this formula shows the expression for three sub-intervals: low, medium, and high; it can be expanded in practical applications); , For low-height regions (such as areas with fine textures), a logarithmic curve is used. >0 is the amplification factor; The larger the value, the more significant the magnification effect in the low-height area; , For the medium altitude range, a linear mapping is used to ensure a natural transition; , ] represents the high-height range (such as the thick coating stacking area), 0 < <1 indicates a compression index. The smaller the value, the stronger the compression effect in the high-altitude region; , These are the minimum and maximum output grayscale values ​​for the corresponding range, which can usually be set to 0 and 255 according to the grayscale response characteristics of the printer.

[0034] The advantages of this formula are: in the low-height range, the logarithmic function has a large slope when the independent variable is small, which can map small height differences into obvious grayscale differences, thereby "amplifying" subtle textures and avoiding loss of detail; in the medium-height range, a linear mapping is used to ensure a smooth transition without abrupt changes; in the high-height range, the power function ( The slope of <1) gradually decreases with increasing height, making the grayscale changes corresponding to large height variations more gradual. This effectively compresses excessively thick stacked information and prevents sagging, cracking, or grayscale saturation distortion caused by exceeding the single or cumulative printing thickness of UV varnish. By adjusting the parameters... and It can flexibly adapt to different oil painting styles (such as classical thin paint and Impressionist thick paint). In practical applications, the total interval can be divided into four or more sub-intervals according to the distribution characteristics of the height statistical histogram, and logarithmic, linear or power function segments of similar form can be constructed for each sub-interval to further improve the mapping accuracy.

[0035] Compared with a single linear mapping or a simple logarithmic / exponential global mapping, this piecewise nonlinear mapping formula takes into account both the detail resolution capability in the low-height region and the stacking compression capability in the high-height region, significantly improving the realism of oil painting 3D texture printing and the reliability of the printing process.

[0036] Specifically, the human eye is sensitive to low-level height changes, but the logarithmic function has a large slope when the independent variable is small, which can map small height differences into large grayscale differences, thus "magnifying" texture details. The exponential function has a gradually increasing slope when the independent variable is large, but in order to compress high-height areas, in practical applications, an exponential decay curve with a base less than 1 or an inverse function of the logarithmic curve is often used, so that the grayscale changes in high-height areas tend to be gentle, preventing stacking distortion caused by the limit of single-layer thickness in printing.

[0037] In the low height range (e.g., 0-0.3mm): a logarithmic curve is used so that a small increment in Z corresponds to a significant increment in G.

[0038] High height range (e.g., >1mm): Use the first part of an exponential curve or a similar S-shaped curve to make G increase slowly when Z increases significantly.

[0039] After generating the grayscale image, the grayscale difference in the lower areas is significant during printing, which can print delicate brushstroke textures; the upper areas will not be over-stacking due to grayscale saturation.

[0040] The above solutions enhance the visual expressiveness of low-height artistic effects such as thin coatings, dry brushing, and transparent glazing. They prevent thick coating areas from exceeding the printer's single or cumulative thickness capacity due to grayscale linear mapping, avoiding "sagging" or "cracking," and are matched to human visual perception characteristics, making the reproduction closer to the viewing experience of the original.

[0041] The edge feathering process in the layered processing step specifically involves: identifying regions in the original grayscale image where the grayscale gradient exceeds a preset threshold, applying Gaussian blurring to these regions, and generating a transitional grayscale image.

[0042] Directly printing sharp grayscale edges causes UV varnish to stack vertically at the edges, forming a "cliff-like" stepped effect, which is very noticeable when viewed at an angle. Gaussian blur is equivalent to gradually reducing the grayscale value near the edge, making the varnish thickness smoothly decrease from the center of the stroke to the edge, forming a sloping transition. A preset threshold is used to distinguish between "flat areas inside the stroke" (small gradient, no processing) and "steep areas at the edge of the stroke" (large gradient, feathering required), avoiding blurring of internal details.

[0043] In this scheme, the gradient magnitude of each pixel is calculated for each original grayscale image (such as the Sobel operator). The region with a gradient threshold T is marked as the edge region. For the pixels in the edge region, a Gaussian kernel (such as σ=3-5 pixels) is applied for convolution to make the grayscale value smoothly decrease from the inside of the edge to the outside, and the processed transition grayscale image is output.

[0044] This printing method produces brushstrokes with natural bevels, eliminating the visual "step-like" effect. It enhances interlayer bonding because the bevel increases the contact area. It simulates the natural, rounded edges of real oil painting brushstrokes caused by the surface tension of the pigment.

[0045] Before the layer printing step, there is also a path planning step: based on the grayscale gradient direction of the layered grayscale image, the scanning direction of the UV inkjet printer is set so that the direction of ink droplet accumulation is consistent with the direction of the brushstrokes of the original oil painting; for areas where the grayscale gradient exceeds the preset threshold, the cross printing mode is enabled.

[0046] During inkjet printing, ink droplets will slightly tail or spread directionally on the substrate along the scanning direction. If the scanning direction is perpendicular to the stroke direction, it will destroy the texture direction of the stroke. Cross printing (first pass in the X direction, second pass in the Y direction) can make ink droplets accumulate at the edges through two orthogonal scans, improving perpendicularity and fill rate, and is especially suitable for steep, independent strokes (such as pigment accumulation points).

[0047] For example, the gradient direction field of the layered printed grayscale image is calculated as the main direction of the brush stroke.

[0048] For regions with consistent gradient directions, set the printing scan direction to have an angle of less than 30° with that direction.

[0049] For regions where the gradient magnitude is greater than the threshold (i.e., steep edges), enable the cross-printing mode: first print one layer along the X-axis, then UV semi-cured; then print a second layer (also a grayscale image) along the Y-axis.

[0050] For flat areas, unidirectional scanning is used to improve efficiency.

[0051] The above method ensures that the texture direction of the printed pattern matches the direction of the original brushstrokes, enhancing visual realism. Cross-printing significantly improves the verticality and shape fidelity of steep edges, prevents "edge collapse," improves the uniformity of ink droplet filling, and reduces porosity.

[0052] The layer printing process specifically includes: printing each layer in order of increasing height; pre-curing each layer using a UV lamp with the highest power; and finally curing all layers using a UV lamp with a higher power than the first power.

[0053] UV varnishes undergo volume shrinkage during the curing process. If each layer is fully cured (high power), the interlayer bonding is weak, and internal stress can easily lead to cracking. Pre-curing (low power) allows the varnish to reach a gel state (approximately 30-50% cure), maintaining its fluidity for cross-linking with the upper molecular chains while preventing excessive flow. Final curing (high power) ensures all layers cure completely simultaneously, forming a unified whole.

[0054] For example, after printing the first layer (the lowest layer), a UV lamp is used to irradiate the surface of the varnish for 0.5 seconds at low power (e.g., 20% power) to cure the surface of the varnish while leaving the interior soft.

[0055] When the second layer is printed, the varnish of the second layer will slightly wet the semi-cured surface of the first layer, forming a chemical bond.

[0056] Repeat the pre-curing process until the top layer is printed.

[0057] Finally, irradiate with high power (e.g., 100%) for 3 seconds to achieve deep and complete curing.

[0058] The above method significantly enhances interlayer adhesion, allowing the replica to withstand bending and scratching. It reduces cracks or deformation caused by volume shrinkage. It maintains the shape of each layer while allowing interlayer fusion, eliminating visible layer interfaces.

[0059] It also includes a closed-loop correction step: during or after the layered printing process, the actual height of the printed texture layer is scanned and compared with the original height in the 3D point cloud data. Based on the comparison results, the nonlinear mapping curve parameters for subsequent printing or the ink jet volume of the UV inkjet printer are dynamically corrected.

[0060] During the printing process, factors such as nozzle clogging, changes in ink viscosity, and substrate warping may cause deviations between the actual height and the design value. Open-loop systems cannot correct this. This solution integrates an online 3D scanner (such as laser triangulation) to acquire the height map of the printed layers in real time and calculate the error point by point. Based on the sign and magnitude of the error, the PID controller adjusts the mapping curve parameters (such as the curve slope) or ink volume (such as increasing or decreasing the number of ink droplets per pixel) for the next layer or subsequent tasks, achieving closed-loop control.

[0061] Specifically, after printing the Nth layer, scan the actual height distribution of that layer. .

[0062] With design height (Data extracted from the corresponding layer in the original point cloud) is compared to obtain the error. .

[0063] like If the value is positive (too low), then the mapping curve of layer N+1 is corrected: increase the inkjet volume corresponding to the gray level, or directly increase the inkjet volume multiplier.

[0064] like If the value is negative (too high), then the inkjet volume of subsequent layers will be reduced.

[0065] After several rounds of corrections, the system converged to high accuracy.

[0066] It compensates for systematic and random errors, ensuring that the height error of batch reproductions is less than ±5%, allowing the use of lower-cost printing components and achieving high precision through software correction. It is adaptable to different substrates and environmental conditions, exhibiting strong robustness.

[0067] Following the data acquisition step, a registration step is also included: spatial coordinate registration of color image data and 3D point cloud data to generate an initial 3D model with color information.

[0068] 3D scanners and color cameras typically have different coordinate systems and resolutions. Registration involves calculating a transformation matrix (such as a rigid or affine transformation) by finding feature points (e.g., canvas corners, prominent brush stroke edges) so that each 3D point (X, Y, Z) corresponds to a pixel value (R, G, B) in the color image. The resulting initial 3D model forms the basis for all subsequent processing.

[0069] Specifically, at least four non-collinear markers are pasted or identified on the surface of the oil painting.

[0070] The 3D coordinates of the marker points are obtained using a 3D scanner, and the pixel coordinates of the marker points are obtained using a color camera.

[0071] Calculate the projection matrix from 3D to 2D (such as camera intrinsic and extrinsic parameters) or directly calculate the thin plate spline transformation.

[0072] Map each 3D point (X,Y) to color image coordinates, extract the RGB values, and append them to the point's attributes.

[0073] The above method ensures that the printed colors accurately correspond to the correct height position, avoiding color and texture misalignment. It provides spatially aligned height and color data for subsequent generation of layered grayscale images, improving the overall visual consistency of the reproduction.

[0074] Before the layer printing step, there is also a color layer printing step: based on the color image data, a color image layer is printed on the substrate and semi-cured; the layer printing step is performed on top of the color image layer.

[0075] The printing material (such as canvas) is fixed on the printing platform, and CMYK or more color layers are printed according to the registered color image data. A UV lamp is used at medium power to irradiate the color layers until they reach a semi-cured state (approximately 70% curing), with active groups still remaining on the surface. Then, transparent varnish is printed layer by layer on top of the color layers using the method described above. This process avoids mixing of the color ink and transparent varnish, which could cause color cloudiness, and improves the adhesion between the color layers and the texture layers, preventing delamination.

[0076] In summary, the high-fidelity printing method and system for 3D oil painting texture based on 3D scanning and layer mapping provided by this invention generates multiple layered grayscale images by statistically partitioning the height data of the oil painting surface and applying nonlinear mapping curves (e.g., using a logarithmic curve to amplify fine textures in low-height areas and an exponential curve to compress excessively thick layers in high-height areas). This effectively overcomes the shortcomings of single linear mapping in simultaneously capturing details and thick paint, significantly improving the resolution and reproduction accuracy of complex brushstroke layers. Combined with edge feathering, brushstroke direction matching scanning direction, and cross-printing mode, it eliminates the step effect common in traditional printing, resulting in natural edge transitions and texture directions consistent with the original artwork. Simultaneously, printing transparent UV varnish layer by layer from low to high and employing a step-by-step pre-curing and final curing strategy enhances interlayer bonding and the physical durability of the reproduction. Furthermore, a closed-loop correction step is introduced, which involves online scanning of the actual printing height and comparing it with the original height (error formula as shown in the figure). By dynamically adjusting mapping curve parameters or inkjet volume, the consistency and fidelity of batch reproduction are significantly improved. Furthermore, the system features a dedicated printhead group with higher nozzle density for transparent varnish, ensuring the horizontal and vertical resolution of texture printing. In summary, this invention achieves high-precision, high-realism, high-consistency, and high-efficiency reproduction of 3D oil painting textures, possessing outstanding substantive features and significant advancements.

[0077] This invention also provides a 3D oil painting texture printing system, which is used to implement the above-described method embodiments; details already described will not be repeated. The terms "module," "unit," and "subunit," etc., used below refer to combinations of software and / or hardware that achieve a predetermined function. Although the system described in the following embodiments is preferably implemented in software, hardware implementation or a combination of software and hardware is also possible and contemplated.

[0078] like Figure 2 As shown, Figure 2 This is a structural block diagram of the oil painting 3D texture printing system of the present invention, which includes: The 3D scanning unit 101 is used to acquire the three-dimensional point cloud data of the original oil painting; The color imaging unit 102 is used to acquire color image data of the original oil painting; Data processing unit 103 is used to execute the data mapping step and the hierarchical processing step; UV inkjet printer 104 is loaded with CMYK color ink and at least one transparent UV varnish, and is used to perform the color layer printing step and the layer printing step. The closed-loop feedback unit 105 includes an online 3D scanner and a comparator for performing the closed-loop correction step.

[0079] This system embodiment is used to implement the above method embodiment. Its working principle and technical effect are the same as those of the above method embodiment, so they will not be described again here.

[0080] like Figure 3 As shown in the figure, an electronic device provided by an embodiment of the present invention includes: a processor 610, a communication interface 620, a memory 630, and a communication bus 640, wherein the processor 610, the communication interface 620, and the memory 630 communicate with each other through the communication bus 640. The processor 610 can call logical instructions in the memory 630 to execute the following method: Data acquisition steps: Acquire color image data and 3D point cloud data containing height information from the original oil painting; Data mapping steps: Based on the statistical distribution characteristics of the height information, the height value is divided into at least four intervals, and the height value in each interval is mapped to grayscale value using a preset nonlinear mapping curve, generating at least four original grayscale images that correspond one-to-one with each interval. Layered processing steps: The original grayscale image is feathered at the edges and layered overlay is performed to generate at least four layered printed grayscale images; Layered printing steps: Based on the layered grayscale images, use a UV inkjet printer to sequentially print transparent UV varnish layers corresponding to each layered grayscale image on the substrate to construct the three-dimensional texture of the oil painting.

[0081] Furthermore, the logical instructions in the aforementioned memory 630 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0082] This invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, is implemented to perform the methods provided in the above embodiments.

[0083] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of various embodiments or some parts of embodiments.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for 3D texturing oil paintings using a 3D scanner and a UV inkjet printer, characterized in that, Includes the following steps: Data acquisition steps: Acquire color image data and 3D point cloud data containing height information from the original oil painting; Data mapping steps: Based on the statistical distribution characteristics of the height information, the height value is divided into at least four intervals, and the height value in each interval is mapped to grayscale value using a preset nonlinear mapping curve, generating at least four original grayscale images that correspond one-to-one with each interval. Layered processing steps: The original grayscale image is feathered at the edges and layered overlay is performed to generate at least four layered printed grayscale images; Layered printing steps: Based on the layered grayscale images, use a UV inkjet printer to sequentially print transparent UV varnish layers corresponding to each layered grayscale image on the substrate to construct the three-dimensional texture of the oil painting.

2. The method according to claim 1, characterized in that, In the data mapping step, the preset nonlinear mapping curves include logarithmic curves and exponential curves; for the range with lower height values, the logarithmic curve is used to amplify fine textures; for the range with higher height values, the exponential curve is used to compress excessively thick stacks.

3. The method according to claim 1, characterized in that, In the data mapping step, the preset nonlinear mapping curve adopts the following piecewise nonlinear mapping formula: ； in, This is the original height value. The mapped grayscale values; , The total height interval is divided into at least four sub-intervals based on the statistical distribution characteristics described above; , (This refers to the low altitude range.) >0 is the amplification factor; [ , () represents the medium altitude range, and a linear mapping is used; , [ represents the high altitude range, 0 <] <1 indicates a compression index; , These represent the minimum and maximum output grayscale values ​​for the corresponding intervals.

4. The method according to claim 1, characterized in that, The edge feathering in the layered processing step specifically involves: identifying regions in the original grayscale image where the grayscale gradient exceeds a preset threshold, performing Gaussian blur processing on these regions, and generating a transitional grayscale image.

5. The method according to claim 1, characterized in that, Before the layered printing step, a path planning step is also included: based on the grayscale gradient direction of the layered grayscale image, the scanning direction of the UV inkjet printer is set so that the ink droplet accumulation direction is consistent with the brushstroke direction of the original oil painting; for areas where the grayscale gradient exceeds a preset threshold, the cross-printing mode is enabled.

6. The method according to claim 1, characterized in that, The layer printing step specifically includes: printing each layer in order of increasing height; pre-curing each layer using a UV lamp with a first power; and finally curing all layers using a UV lamp with a second power higher than the first power.

7. The method according to claim 1, characterized in that, It also includes a closed-loop correction step: during or after the layered printing process, the actual height of the printed texture layer is scanned and compared with the original height in the three-dimensional point cloud data. Based on the comparison result, the parameters of the nonlinear mapping curve or the ink jet volume of the UV inkjet printer for subsequent printing are dynamically corrected.

8. The method according to claim 1, characterized in that, Following the data acquisition step, a registration step is also included: spatial coordinate registration of the color image data and the three-dimensional point cloud data to generate an initial three-dimensional model with color information.

9. The method according to claim 1, characterized in that, Before the layer printing step, a color layer printing step is also included: printing a color image layer on the substrate according to the color image data and performing a semi-curing treatment; the layer printing step is performed on the color image layer.

10. A 3D texture printing system for oil paintings for implementing the method of any one of claims 1-8, characterized in that, include: The 3D scanning unit is used to acquire the three-dimensional point cloud data of the original oil painting; A color imaging unit is used to acquire color image data of the original oil painting; The data processing unit is used to execute the data mapping step and the hierarchical processing step; A UV inkjet printer, loaded with CMYK color ink and at least one transparent UV varnish, is used to perform the color layer printing step and the layer printing step. The closed-loop feedback unit, including an online 3D scanner and a comparator, is used to perform the closed-loop correction step.

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